You don’t have to live in Northern Nevada long to know it can be windy here. Even on days when there are not any Red Flag Warnings, we always want to stay fire aware year-round. Especially, during the summer and early fall. The Washoe Zephyr kicks in almost every evening during the summer season, which is a local name for a wind that develops between 5-9 pm in the Reno area. Wind gusts range from about 15-25 mph. Occasionally, wind gusts can reach 30 mph as well.
The wind direction is out of the west, and is created by pressure and temperature differences between the Sierra and central Nevada. Forecasters typically compare the temperature in Truckee to Lovelock to calculate evening wind speeds. For example, if it is 90 degrees in Lovelock and 70 in Truckee, then the Washoe Zephyr will more than likely be gusting around 30 mph. If there is a system moving through, the Washoe Zephyr will likely be stronger than normal.
Red Flag Warnings are typically issued for longer durations of critical fire danger, with slightly stronger wind gusts than your average afternoon wind in Reno. With that being said, a breeze of 25 mph can still make a fire spread. Calm winds are ideal.
The Washoe Zephyr is created by circulations in the atmosphere, driven by differences in pressure and temperature. For example, it’s a hot summer day in Lovelock with temperatures around 90 degrees. This heat allows the air to rise at the surface, leaving an area of low pressure near the ground. As the air rises it gets displaced and moves to the west. The air then sinks on the other side of the mountain, creating high pressure at the surface. Wind goes from high to low pressure, leading to a west wind.
